Hitherto, the moving unit of this type has been disclosed in WO 2005/031082 A1. This moving unit disclosed in WO 2005/031082 A1 is used for freely moving furniture items, electric appliances, and the like on a wall surface of buildings. This moving unit includes a pair of track rails being laid on the wall surface in parallel to each other and each having rolling surfaces for rolling elements, which are formed along a longitudinal direction of the track rails, a plurality of moving blocks assembled to the track rails through intermediation of a large number of the rolling elements that roll on the rolling surfaces of the track rails, and a movable body fixed to the moving blocks and guided along the track rails on the wall surface. Examples of the movable body may include a base plate for fixing electric appliances such as a television or furniture items, and casings themselves of the electric appliances. This moving unit enables such movable bodies to be freely moved on the wall surface.
Further, the moving unit of this type may be used to, for example, move various devices, interior equipment, and the like in a large space such as passenger cabins in aircrafts, ships, or trains so that those devices and interior equipment are arranged at arbitrary positions in the space. Specifically, in a passenger cabin of an aircraft, service units are provided correspondingly to respective seats. Those service units each contain emergency supplies such as an oxygen mask, and devices such as a seat number indication and a reading light are mounted to the service units. When those service units can be moved along a ceiling surface in the passenger cabin and fixed at arbitrary positions, an array pitch of the seats in the passenger cabin can be changed significantly easily.